EP0195575B1

EP0195575B1 - Improved lipstick formulation and method

Info

Publication number: EP0195575B1
Application number: EP86301694A
Authority: EP
Inventors: Clara Garcia Mercado; Ann Marshall Krog
Original assignee: Charles of the Ritz Group Ltd
Current assignee: Charles of the Ritz Group Ltd
Priority date: 1985-03-21
Filing date: 1986-03-10
Publication date: 1989-12-27
Also published as: ATE48938T1; EP0195575A1; DE3667748D1

Abstract

An improved lipstick formulation is provided which is creamy, shiny and soft, yet maintains its structural integrity and has excellent color laydown and includes an acrylates copolymer powder together with conventional lipstick ingredients.

Description

The present invention relates to a new lipstick formulation which has unique color laydown properties primarily due to the presence therein of an acrylates copolymer powder.
Lipsticks have been used for many years to impart color to the lips. The color helps to define the mouth area while imparting cosmetic shades that are suitable with fashion trends. Such lipsticks, in general, are made of an oily vehicle comprising fat or oil stiffened to a desired consistency with waxes of various types which also serve to raise the melting point and improve the physical stability. The color is ordinarily provided by insoluble pigments such as lakes of dye finely dispersed in the oily vehicle and one or more fluorescein dye derivatives which serve to stain the lips. A solvent for the dye is also included for increasing the effectiveness of this staining on the lips.
In recent years, attemps have been made to provide a lipstick which will impart a uniform long-lasting coloring to the lips and thus lessen the need for frequent reapplication. This has been accomplished by increasing the concentration of the dye and pigment in the conventional lipstick formulation to greater than 10% by weight. However, lipsticks containing such high concentrations of dye and pigment have been found to impart a dry non-uniform "cakey" look to the lips. This is particularly undesirable since current fashion trends are directed to producing a "we" or "moist" look on the mouth. As a result, emollients, lubricants, and moisturizers are added in increased amount to counteract the "cakey" results of the high dye and pigment containing lipstick formulations. However, these materials may impart a soft mushy easily breakable structure to the lipstick. Furthermore, these materials themselves are usually short-lived on the mouth since they are mechanically removed. In addition, these materials tend to act as vehicles for the dyes and pigments causing "creeping" or "feathering" on the outer edges of the mouth. This eliminates the sharp line of definition of the mouth area for which the product is applied.
US Patent US-A 3,911,105 discloses lipstick compositions which contain polymers having the repeating unit -CH₂-C(R_i)(COOR₂)- where R₁ is H or CH₃ and R₂ is a saturated linear or branched hydrocarbon group of 10-20 carbon atoms. The lipsticks containing these polymers are said to have improved resistance to breaking, brilliance and holding power of the film deposited on the lips.
As hereinafter described, a new creamy soft lipstick formulation is provided which has excellent laydown properties so that it may impart uniform long-lasting coloring to the lips and has excellent structural integrity properties so it will not easily break or become mushy, but stays intact. Furthermore, the lipstick formulation does not contain inordinately high amounts of pigment and/or dye so that it will not impart an undesirable dry "cakey" look to the lips. The improved laydown properties of the lipstick formulation is achieved, at least in part, through the inclusion of an acrylate polymer powder therein.
According to one aspect, the invention provides a lipstick formulation which is soft but has good stick structure, is creamy and shiny, and has good laydown and color-wear properties, said formulation comprising from about 40 to about 80% by weight anhydrous base intermediate comprising one or more waxes and one or more oils; from about 8 to about 35% by weight of a color intermediate which includes an oil dispersing agent; and an anhydrous acrylate polymer powder dispersion intermediate comprising an acrylate polymer powder and oil dispersing agent for said acrylate polymer powder, wherein the acrylate polymer (i) has the repeating unit
(ii) has an average molecular weight within the range of from about 100,000 to about 500,000, and (iii) is present in an amount within the range of from about 0.1 to about 4% by weight of the lipstick formulation.
According to another aspect, the invention provides a method for preparing an improved lipstick formulation which has good laydown properties, creaminess and shininess, and good color wear and stick strength, said method comprising incorporating in an anhydrous lipstick formulation (A) an anhydrous acrylate polymer powder dispersion intermediate comprising (a) an acrylate polymer powder wherein the acrylate polymer (i) has the repeating unit

(ii) has an average molecular weight within the range of from about 100,000 to about 500,000, and (iii) is present in an amount within the range of from about 0.1 to about 4% by weight of the lipstick formulation, and (b) an oil dispersing agent for said acrylate polymer powder, and (B) from about 8 to about 35% by weight of a color intermediate which includes an oil dispersing agent.
The preferred lipstick formulation of the invention is formed of from about 40 to about 80% and preferably from about 50 to about 70% by weight of anhydrous base intermediate which will be fully described hereinafter; from about 3 to about 20% by weight and preferably from about 5 to about 15% by weight of one or more dispersing oils for organic pigments, from about 8 to about 35% by weight and preferably from about 12 to about 30% by weight of color intermediate comprised of a mixture of pigments, dyes or colors and one or more dispersing oils or other softeners, optionally antioxidant and optionally perserva- tive; from about 0.5 to about 5% by weight and preferably from about 1 to about 3% by weight of the acrylate polymer intermediate, which includes from about 0.1 to about 4% and preferably from about 0.2 to about 2.5% by weight of the acrylate polymer by itself to impart and enhance laydown properties of the formulation, and optionally from about 0 to about 1% and preferably from about 0.1 to about 0.8% by weight fragrance, all of the above % being based on the total lipstick formulation. The ingredients of the preferred formulation will now be described in more detail.
The acrylate polymer intermediate will generally be formed of from about 20 to about 80% by weight acrylate polymer powder and from about 80 to about 20% by weight of one or more dispersants therefor, such as castor oil, mineral oil, isopropyl isostearate, oleyl alcohol, liquid lanolin, sesame oil, isopropyl myristate, isopropyl palmitate, squalene and the like, with castor oil being preferred.
The acrylate polymer powder will preferably have an average particle size of within the range of from about 270 to about 325 mesh (0.044-0.053 mm sieve opening).
The preferred acrylate polymers have the repeating unit
A most preferred acrylate polymer powder is Polytrap 249 polymer powder which has the repeating unit formula
which has an average molecular weight within the range of from about 100,000 to about 500,000 and is marketed by Wickhen Products, Incorporated, Chemical Specialty Products, Huguenot; New York and has a bulk density of from about 0.52 to about 0.57, a flash point of greater than 300_°F (149_°C) and a particle size so that about 30% is retained on a 270 mesh screen and about 4% is retained on a 325 mesh screen.
The anhydrous base intermediate will generally be formed of one or more external stick strengtheners in an amount of within the range of from about 5 to about 20% by weight and preferably from about 8 to about 16% by weight based on the weight of the total lipstick formulation. Such external stick strengtheners provide one or more of the follwing properties: impart structural intergrity to the lipstick, provide hardness, provide mold release properties, and stick strength and drag on the lips. Examples of external stick strengtheners suitable for use herein include waxes such as candelilla, ozokerite, carnauba, beeswax and the like or mixture of two or more of such waxes.
One or more wax feel enhancers and structure strentheners will also be included in the base intermediate in an amount within the range of from about 5 to about 20% by weight and preferably from about 9 to about 16% by weight of the total lipstick formulation. Examples of such wax feel enhancers and structure strengtheners include cetyl alcohol, stearyl alcohol, lanolin USP, super wool wax (a lanolin alcohol fraction), glyceryl monostearate and the like or mixtures thereof.
The best intermediate will also contain an internal stick strengthener in an amount within the range of from about 0.5 to about 10% by weight and preferably from about 1 to about 6% by weight based on the total stick formulation. A preferred internal stick strengthener is paraffin wax. Other examples are ozokerite wax or carnauba wax.
One or more feel enhancers in cream form will also be included in the base intermediate in an amount within the range of from about 1 to about 10% by weight and preferably from about 2 to about 7% by weight based on the total stick formulation. Examples of suitable cream feel enhancers include hydrogenated vegetable oil, isopropyl lanolate, synthetic cocoa butter, acetylated lanolin alcohol and lanolin derivatives or mixtures thereof.
One or more lip moisturizers, emollients, lubricants and/or glide or slip agents will be present, such as petrolatum white (which is a slip moisturizer), oleyl alcohol (a penetrant), castor oil, low viscosity mineral oils (which are glide or slip agents, emollients and/or moisturuzers), liquid lanolin, and/or jojoba oil (which are shine enhancers), isopropyl myristate, isopropyl palmitate, squaline and/or sesame oil (which are lubricants), and the like will also be present in the base intermediate in amounts within the range of from about 3 to about 30% by weight and preferably from about 5 to about 25% by weight based on the total weight of the stick formulation. It is preferred to employ a mixture of these oils for their different functions.
A coupling agent for waxes and oils will also be present in the anhydrous base intermediate in an amount within the range of from about 6 to about 20% by weight and preferably from about 8 to about 15% by weight of the total formulation. Examples of suitable coupling agents include oleyl alcohol, dipropyl diperlargonate or caster oil or mixtures thereof.
The base intermediate may optionally include one or more preservatives in amounts of less than about 0.3% and preferably less than about 0.2% by weight of the total lipstick formulation, such as propyl p-hydroxybenzoate (propyl paraben), methyl p-hydroxybenzoate (methyl paraben) and/or butyl p-hydroxybenzoate (butyl paraben), and optionally less than about 0.05% by weight of an antioxidant such as butylated hydroxyanisole, or Vitamin E tocopherol, and other moisturizers such as wheat germ glycerides and hydrolyzed animal protein.
The color intermediate will contain from about 25 to about 40% by weight of one or more dyes and/or pigments, from about 55 to about 75% by weight and preferably from about 60 to about 70% by weight of one or more color dispersants, such as any of those set out above and used for dispersing the acrylate polymer, with castor oil being preferred, optionally less than about 0.05% and preferably less than about 0.03% by weight antioxidant, such as set out above with respect to the base intermediate, and optionally less than about 0.3% by weight and preferably less than about 0.2% by weight preservative, such as set out above with respect to the base intermediate, all of the above percentages being base on the total weight of the color intermediate.
The dyes employed in the formulation are the U.S. Government certified colors, both Drug and Cosmetic grade, and Food, Drug and Cosmetic grade. The pigments employed are of the inorganic grade such as iron oxides, titanium dioxide, iron sulfides, or other conventional pigments approved for cosmetic use.
Anhydrous natural flavor and fragrance oils such as peppermint oil, lemon oil, orange oil, etc. or synthetic flavor and fragrance oils may optionally be included in the lipstick formulation by incorporation into the anhydrous base or even into the color intermediate, in amounts of less than about 1% by weight of the lipstick formulation and preferably from about 0.1 to about 0.8% by weight.
The lipstick when applied coats the lips with the acrylate polymer causing the color or pigment to easily laydown in a creamy uniform manner with the colors penetrating every pore and crevice on the lip surface.
Preferred lipstick formulations in accordance with the present invention are set out below.
The lipstick formulation of the invention may be prepared by forming a mixture of the anhydrous base intermediate ingredients wherein the waxes are melted and the oil components are added with agitation to form the anhydrous base intermediate. The base intermediate and softener (castor oil) are heated to 75 to 85_°C with propeller mixing until a liquid is formed.
The color intermediate phase (formed by adding the color to the dispersant, heating with agitation at 65 to 75_°C and then roller milling three times) is added to the base intermediatesoftener phase with mixing for 40 to 80 minutes.
Next, the acrylate polymer intermediate (formed by adding the polymer to the dispersant and roller milling 3 times) is added to the mix and mixing is continued for 20 to 35 minutes until a uniform mixture is obtained. Fragrance (where present) is then added and mixing is continued for 10 minutes.
The mixture is then molded to form the lipstick formulation of the invention.
The following Examples represent preferred embodiments of the present invention.

Example 1

A lipstick formulation having the following composition is prepared as described below.

1. All of the waxes were melted in a steam-jacketed kettle with propeller mixer agitation while maintaining the temperature at from 75 to 85_°C. After the waxes were melted, the oil components except for the castor oil and the remaining components of the base intermediate were added and agitation was continued.
2. The dyes, pigments, preservative and antioxidant were added to the castor oil in a separate kettle and heated with agitation at 70_°C. Agitation was continued until a proper dispersion achieved. The dispersion of oil and coloring agent were passed through a three-roll mill. The color dispersion was added to the base intermediate with mixing for 40 to 60 minutes.
3. The acrylate polymer dispersed in castor oil and roller milled three times was added to the above mixture with mixing for 20 to 30 minutes until a uniform mixture was obtained.
4. Fragrance was then added with mixing for 10 minutes.

The resulting lipstick formulation was poured into molds and refrigerated to form the lipstick.
It was found that the lipstick formulation of the invention incorporating the acrylate polymer powder was soft but had good structure, was creamy, shiny and had excellent laydown.

Example 2

Following the procedure of Example 1, a lipstick formulation was prepared having the following composition.
It was found that the lipstick formulation of the invention incorporating the acrylate polymer powder was soft but had good structure, was creamy, shiny and had excellent color laydown.

Claims

1. A lipstick formulation which is soft but has good stick structure, is creamy and shiny, and has good laydown and color-wear properties, said formulation comprising from about 40 to about 80% by weight anhydrous base intermediate comprising one or more waxes and one or more oils; from about 8 to about 35% by weight of a color intermediate which includes an oil dispersing agent; and an anhydrous acrylate polymer powder dispersion intermediate comprising an acrylate polymer powder and an oil dispersing agent for said acrylate polymer powder, wherein the acrylate polymer (i) has the repeating unit

or

(ii) has an average molecular weight within the range of from about 100,000 to about 500,000, and (iii) is present in an amount within the range of from about 0.1 to about 4% by weight of the lipstick formulation.

2. The lipstick formulation as defined in claim 1 wherein the acrylate polymer is present in an amount within the rage of from about 0.2 to about 2.5% by weight of the lipstick formulation.

3. The lipstick formulation as defined in claim 1 or 2 wherein the acrylate polymer has the repeating unit

4. The lipstick formulation as defined in any one of claims 1-3 wherein the anhydrous base intermediate is present in an amount within the range of from about 50 to about 70% by weight of the lipstick formulation.

5. The lipstick formulation as defined in any one of Claims 1-4 wherein the base intermediate includes one or more external stick strengtheners, one or more wax feel enhancers and structure strengtheners, one or more internal stick stengtheners, one or more feel enhancers in cream form, one or more lip moisturizers, emollients, lubricants and/or glide or slip agents, one or more coupling agents for waxes and oils, optionally one or more preservatives and optionally one or more antioxidants.

6. The lipstick formulation as defined in Claim 5 wherein the external stick strengthener is present in an amount within the range of from about 5 to about 20% by weight of the total formulation and is candelilla wax, paraffin wax, carnauba wax, beeswax or a mixture thereof.

7. The lipstick formulation as defined in Claim 5 or 6 wherein the wax feel enhancer and structure strengthener is present in an amount within the range of from about 5 to about 18% by weight of the total formulation and is cetyl alcohol, stearyl alcohol, lanolin, lanolin alcohol, glyceryl monostearate or a mixture thereof.

8. The lipstick formulation as defined in Claim 5, 6 or 7 wherein the internal stick strengthener is present in an amount within the range.of from about 0.5 to about 5% by weight of the total formulation and is paraffin wax, carnauba wax or ozokerite wax.

9. The lipstick formulation as defined in Claim 5, 6, 7 or 8 wherein the feel enhancer in cream form is present in an amount within the range of from about 1 to about 10% by weight of the total formulation and is hydrogenated vegetable oil, isopropyl lanolate, cocoa butter, acetylated lanolin alcohol, lanolin derivatives or a mixture thereof.

10. The lipstick formulation as defined in Claim 5, 6, 7, 8 or 9 wherein the lip moisturizers, emollients, lubricants and/or glide or slip agents are present in an amount within the range of from about 3 to about 30% based on the total formulation and are petrolatum white, oleyl alcohol, castor oil, low viscosity mineral oil, liquid lanolin, jojoba oil, isopropyl myristate, isopropyl palmitate, squalane, sesame oil or a mixture thereof.

11. The lipstick formulation as defined in Claim 5, 6, 7, 8, 9 or 10 wherein the coupling agent for waxes and oils is present in an amount within the range of from about 6 to about 15% by weight of the total formulation and is oleyl alcohol, dipropyl dipelargonate, castor oil or a mixture thereof.

12. The lipstick formulation as defined in any preceding claim wherein said oil dispersing agent is castor oil, mineral oil, isopropyl isostearate, oleyl alcohol, liquid lanolin, sesame oil, isopropyl myristate, isopropyl palmitate, or squalene.

13. A method for preparing an improved lipstick formulation which has good laydown properties, creaminess and shininess, and good color wear and stick strength, said method comprising incorporating in an anhydrous lipstick formulation (A) an anhydrous acrylate polymer powder dispersion intermediate comprising (a) an acrylate polymer powder wherein the acrylate polymer (i) has the repeating unit

or

(ii) has an average molecular weight within the range of from about 100,000 to about 500,000, and (iii) is present in an amount within the range of from about 0.1 to about 4% by weight of the lipstick formulation, and (b) an oil dispersing agent for said acrylate polymer powder, and (B) from about 8 to about 35% by weight of a color intermediate which includes an oil dispersing agent.